The present invention relates a surgical staple, for closing a puncture site in a liquid-carrying vessel in a human or animal body, for example a blood vessel, by applying a staple across the puncture so as to affect a closure and prevent bleeding. The invention also relates to a method of stapling using such a staple.
When performing catheterisation procedures, such as angiography or angioplasty, a catheter is generally introduced into the vascular system by first penetrating the skin, underlying tissues and blood vessel with a sharpened hollow needle. Next, a guidewire is commonly inserted through the lumen of the hollow needle and is caused to enter the selected blood vessel. Subsequently the needle is typically stripped off the guidewire and a combination of a dilator and/or introducer (or an introducer alone) are fed over the guidewire and pushed through the skin to enter the blood vessel. The guidewire can then be removed and a desired catheter to carry out the procedure is fed through the lumen of the introducer and advanced through the vascular system until the working end of the catheter is appropriately positioned. Following the conclusion of the catheterisation procedure the working catheter will be withdrawn and subsequently the dilator and/or introducer will also be removed from the wound. Following this procedure the vessel puncture must be closed in order to prevent loss of blood through the puncture hole.
Typically the wound is closed by maintaining external pressure over the vessel until the puncture naturally seals. This procedure can take approximately 30 minutes with the length of time usually being greater if the patient is hypertensive or anticoagulated. The procedure can also be uncomfortable for the patient and involves costly professional time on the part of the hospital staff. Other pressure techniques such as pressure bandages, sandbags or clamps have been employed but these also involve ensuring the patient remains motionless for an extended period of time and is monitored to ensure the effectiveness of the procedure.
A number of devices have been developed in recent times which provide an obstruction in the area of the puncture in order to prevent bleeding. For example, U.S. Pat. Nos. 4,852,568 and 4,890,612 disclose a device which utilises a collagen plug which when placed at the blood vessel opening absorbs body fluids, swells and affects a seal. Other plug like devices, for example U.S. Pat. Nos. 5,222,974 and 5,282,827, describe a plug and anchor device, the anchor being positioned inside the vessel and the collagen plug outside the vessel thereby sandwiching the puncture between both and effecting a closure.
WO 98/17179 discloses a surgical stapler having a blood locator tube adjacent the stapling head. A guidewire passes through an opening at the end of the tube and up through a hollow bore in the tube, so that the stapler can be fed onto the guidewire and down onto the puncture site. When the device reaches the puncture site, the tip of the tube enters the blood flow within the artery and blood passes through the tube and out of the distal end at a point visible to the clinician. The clinician can then actuate the stapling mechanism in the knowledge that the stapling head is at the puncture site in the arterial wall.
It is an object of the present invention to provide an improved surgical staple for closing a puncture in a liquid-carrying vessel. It is a further object of the invention to provide an improved method of stapling using such a staple.
According to the present invention there is provided a surgical staple comprising a base portion and a respective leg extending from each end of the base portion and terminating at a free end, the base portion being deformable to bring the free ends of the legs together to penetrate a liquid-carrying vessel at the site of a puncture and hold the opposite edges of the puncture together, the base portion and legs lying in substantially a common plane except for a center portion of the base portion which is deformed in a loop at an angle to the common plane.
In another aspect the invention provides a method of stapling closed a puncture site in a liquid-carrying vessel in a human or animal body, comprising the steps of:
introducing a stapling mechanism to the location of the vessel;
positioning the stapling mechanism at the puncture site by means of an elongated locator device associated with the stapling mechanism, the locator device sensing the position of the puncture site by entering the vessel at the site; and
delivering a staple to, and deforming the staple to close, the puncture site;
wherein the staple comprises a base portion and a respective leg extending from each end of the base portion and terminating at a free end, the base portion being deformable to bring the free ends of the legs together to penetrate a blood vessel at the site of a puncture and hold the opposite edges of the puncture together, the base portion and legs lying in substantially a common plane except for a center portion of the base portion which is deformed in a loop at an angle to the common plane; and
wherein during delivery of the staple to the puncture site the staple loop straddles and slides along the locator device.